<h1>Request Group Rate</h1>
<form>
    <input type="hidden" name="referrer">
    Name:<input type="text" id="fieldName" name="name">
    Group:<input type="text" name="groupSize">
    Email:<input type="email" name="email">
    <input type="submit" value="Submit">
</form>
<script>
    $(function(){
        $("input[name='referrer']").val(document.referrer);
    });
</script>